Down-regulation of hepatic PPARg and C/EBPa genes in Juvenile-stage zebrafish exposured chronically to bisphenol A

Bisphenol A (BPA) is used in synthesis of plastics. It is known as a potential chemical that causes hormonal changes in human and animals. Many previously studies showed that the activity of BPA was similar to estrogen and it could affect on embryonic and newborn stages. From a different approach, a research by these authors published in 2017 suggested that BPA could effect to the fast- growing stage of an animal based on proteomic profiles of Juvenile-stage zebrafish livers long term exposured to mg/L range of the chemical. This study was the extent of that research to further investigate which metabolic receptors in liver effected by BPA exposure. Among suggestedhepatic receptors, PPARg and C/EBPa genes may be targeted by BPA under such exposure condition. Methods: In this study, zebrafish at 30th day of age were exposed to 0, 10 and 100 mg /L BPA, respectively, and continuously for 60 days under a standar condition for testing chronic toxicity of a chemical on fish. At the end of the testing, mRNA levels of PPARg and C/EBPa genes in zebrafish livers of BPA-exposed groups were compared to that of BPA-unexposed group using Real-Time PCR method with b -actin gene as the reference gene. Results: BPA affected transcription level of both genes depending on the concentration of the chemical. Reduction of 67% and 70% on mRNA level for PPARg and C/EBPa, respectively, was only observed on 100 mg/L BPA-exposed group. No significant change on such regulation was found in 10 mg/L BPA-exposed group. Conclusion: Thus, the effect of BPA exposure on liver functions of zebrafish at juvenile stage may associate with hepatic PPARg and C/EBPa receptors and it depends on the chemical concentration.